Making Data Meaningful Part 2: a Guide to Presenting Statistics

Total Page:16

File Type:pdf, Size:1020Kb

Making Data Meaningful Part 2: a Guide to Presenting Statistics UNITED NATIONS ECONOMIC COMMISSION FOR EUROPE Making Data Meaningful Part 2: A guide to presenting statistics UNITED NATIONS Geneva, 2009 NOTE The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontier or boundaries. ECE/CES/STAT/NONE/2009/3 Table of Contents ……………………………… Introduction ...................................................................................................v 1. Getting the message across ........................................................................ 1 2. Visualization of statistics ............................................................................. 7 3. Tables ..................................................................................................... 12 4. Charts ..................................................................................................... 17 5. Maps ....................................................................................................... 30 6. Emerging visualization techniques ............................................................... 41 7. Accessibility issues .................................................................................... 46 8. References and further reading ................................................................... 51 iii Making Data Meaningful Part 2: A guide to presenting statistics Introduction The Making Data Meaningful guides have been prepared within the framework of the United Nations Economic Commission for Europe (UNECE) Work Sessions on the Communication and Dissemination of Statistics1, under the programme of work of the Conference of European Statisticians2. These guides are intended as a practical tool to help managers, statisticians and media relations officers in statistical organizations, particularly those organizations that are in the process of developing their communication strategies. The guides provide advice on the use of text, tables, charts, maps and other devices to bring statistics to life for non-statisticians. They contain suggestions, guidelines and examples - but not strict rules or rigid templates. An effective data release uses a combination of text, tables and graphics to maximize its strength in conveying various types of information. Making Data Meaningful Part 1: A guide to writing stories about numbers (issued in 2006) focused on the use of effective writing techniques. Making Data Meaningful Part 2: A guide to presenting statistics aims to help readers find the best way to get their message across to non-specialists, using the most suitable set of tools and skills now available from a dazzling array of communication methods. This guide recognizes that there are many practical and cultural differences among statistical organizations and that approaches may vary from country to country. A group of experts in the communication and dissemination of statistics prepared this guide. They are (in alphabetical order): Petteri Baer, UNECE Colleen Blessing, United States Energy Information Administration Eileen Capponi, Organisation for Economic Co-operation and Development Jerôme Cukier, Organisation for Economic Co-operation and Development Kerrie Duff, Australian Bureau of Statistics John Flanders, Statistics Canada Colleen Flannery, United States Census Bureau Jessica Gardner, UNECE Martine Grenier, Statistics Canada Armin Grossenbacher, Swiss Federal Statistical Office David Marder, United Kingdom Office for National Statistics Kenneth Meyer, United States Census Bureau Terri Mitton, Organisation for Economic Co-operation and Development Eric St. John, Statistics Canada Thomas Schulz, Swiss Federal Statistical Office Anne-Christine Wanders, UNECE The contributions of Martin Lachance (Statistics Canada), Andrew Mair (Australian Bureau of Statistics), Alan Smith (United Kingdom Office for National Statistics), Christina O’Shaughnessy and Steven Vale (UNECE) are greatly appreciated. 1 Information about the UNECE Work Sessions on the Communication and Dissemination of Statistics are available from the UNECE website at http://www.unece.org/stats/archive/04.05.e.htm. 2 Information about the Conference of European Statisticians is available from the UNECE website at http://www.unece.org/stats/archive/act.00.e.htm. v Making Data Meaningful Part 2: A guide to presenting statistics 1. Getting the message across 1.1 The written word News releases are often the vehicle through which your statistical organization communicates key findings of its statistical and analytical programmes to the intended audience, which is most probably the general public. The text is the principal vehicle for explaining the findings, outlining trends and providing contextual information. In this chapter, we will provide many suggestions for preparing an “effective” news release or other document, such as a report or an analytical article. What makes a news release, report or analytical article effective? Perhaps the best explanation comes from the first Making Data Meaningful guide, Part 1: A guide to writing stories about numbers, which provides an initial set of recommendations for getting your message across. An effective news release is one that: tells a story about the data; has relevance for the public and answers the question “Why should my audience want to read about this?”; catches the reader's attention quickly with a headline or image; is easily understood, interesting and often entertaining; encourages others, including the media, to use statistics appropriately to add impact to what they are communicating. Here are some tips to help you get started on your text. 1.2 Target audience: your first decision The first important decision you must make is to pinpoint an audience: who are you writing for? Quite simply, the audience is in the driver's seat. By and large, what the audience wants is what you should be giving them. You have to listen to your audiences to find and select the right narratives, language, and visual and graphic devices that will capture their attention. The choice of an audience is more complex these days because of the Internet. Most statistical organizations have a mandate to communicate to the general public, who are non-specialized, fairly well-educated laypeople. In the days of printed news releases, the principal target audience was likely to be the media, on which organizations relied to transmit key findings to the public. Nowadays, however, statistical organizations have developed a significant direct readership through their websites, e-mail and other forms of Internet-based distribution. This means that they are communicating with a host of audiences simultaneously: the public, data users, bankers, financial analysts, university professors, students and so on, each with their own data requirements. 1 Making Data Meaningful Part 2: A guide to presenting statistics The communications world is constantly evolving. Successful commercial media know this and constantly monitor - often in real time - which of their stories get the most attention. They then target their resources to create richer content by using devices such as video, additional photos or more analysis to encourage greater interaction with each audience. In any case, the message here is that before throwing precious resources into any method of communication - new or established - it is important to decide first who your audiences or stakeholders are, what it is they want from you and how they want it. Should you wish to address several audiences, you must select the most appropriate method to reach each of them, by transmitting your message through appropriate channels and using appropriate communication techniques. Often though, lack of time and resources mean that it is not possible to reach all of your audiences all of the time. You have a choice: you can prioritize or, if you want to reach the widest audience, you can find the clearest common ground. This is what many statistical organizations do. They target the general public, but make a concerted effort to reach this audience by using journalists as a kind of 'conduit'. The intended audience is the public, but journalists are the means of communicating with that audience. Experts and specialists also benefit from this approach. Often, the simple clear techniques used to reach a wide audience are warmly welcomed by even the most specialized audience. 1.3 Understand the context in which you are communicating Statistical communication does not occur in isolation. Therefore, it is important that you understand the context in which you are communicating. The way in which audiences consume media is constantly changing. There are also distinct differences between generations, in their technical abilities and understanding of statistics. When planning statistical communication, you should keep in mind four particular trends in online media consumption, which represent both opportunities and risks: 1. The World Wide Web is increasingly becoming a medium for entertainment. Any message that is not presented in an interesting way risks not engaging with younger audiences. 2. Society has developed a “snack culture” in relation to information consumption. Audiences increasingly want smaller snippets of information that can be consumed quickly. 3. Audiences using
Recommended publications
  • Fundamental Statistical Concepts in Presenting Data Principles For
    Fundamental Statistical Concepts in Presenting Data Principles for Constructing Better Graphics Rafe M. J. Donahue, Ph.D. Director of Statistics Biomimetic Therapeutics, Inc. Franklin, TN Adjunct Associate Professor Vanderbilt University Medical Center Department of Biostatistics Nashville, TN Version 2.11 July 2011 2 FUNDAMENTAL STATI S TIC S CONCEPT S IN PRE S ENTING DATA This text was developed as the course notes for the course Fundamental Statistical Concepts in Presenting Data; Principles for Constructing Better Graphics, as presented by Rafe Donahue at the Joint Statistical Meetings (JSM) in Denver, Colorado in August 2008 and for a follow-up course as part of the American Statistical Association’s LearnStat program in April 2009. It was also used as the course notes for the same course at the JSM in Vancouver, British Columbia in August 2010 and will be used for the JSM course in Miami in July 2011. This document was prepared in color in Portable Document Format (pdf) with page sizes of 8.5in by 11in, in a deliberate spread format. As such, there are “left” pages and “right” pages. Odd pages are on the right; even pages are on the left. Some elements of certain figures span opposing pages of a spread. Therefore, when printing, as printers have difficulty printing to the physical edge of the page, care must be taken to ensure that all the content makes it onto the printed page. The easiest way to do this, outside of taking this to a printing house and having them print on larger sheets and trim down to 8.5-by-11, is to print using the “Fit to Printable Area” option under Page Scaling, when printing from Adobe Acrobat.
    [Show full text]
  • Interactive Statistical Graphics/ When Charts Come to Life
    Titel Event, Date Author Affiliation Interactive Statistical Graphics When Charts come to Life [email protected] www.theusRus.de Telefónica Germany Interactive Statistical Graphics – When Charts come to Life PSI Graphics One Day Meeting Martin Theus 2 www.theusRus.de What I do not talk about … Interactive Statistical Graphics – When Charts come to Life PSI Graphics One Day Meeting Martin Theus 3 www.theusRus.de … still not what I mean. Interactive Statistical Graphics – When Charts come to Life PSI Graphics One Day Meeting Martin Theus 4 www.theusRus.de Interactive Graphics ≠ Dynamic Graphics • Interactive Graphics … uses various interactions with the plots to change selections and parameters quickly. Interactive Statistical Graphics – When Charts come to Life PSI Graphics One Day Meeting Martin Theus 4 www.theusRus.de Interactive Graphics ≠ Dynamic Graphics • Interactive Graphics … uses various interactions with the plots to change selections and parameters quickly. • Dynamic Graphics … uses animated / rotating plots to visualize high dimensional (continuous) data. Interactive Statistical Graphics – When Charts come to Life PSI Graphics One Day Meeting Martin Theus 4 www.theusRus.de Interactive Graphics ≠ Dynamic Graphics • Interactive Graphics … uses various interactions with the plots to change selections and parameters quickly. • Dynamic Graphics … uses animated / rotating plots to visualize high dimensional (continuous) data. 1973 PRIM-9 Tukey et al. Interactive Statistical Graphics – When Charts come to Life PSI Graphics One Day Meeting Martin Theus 4 www.theusRus.de Interactive Graphics ≠ Dynamic Graphics • Interactive Graphics … uses various interactions with the plots to change selections and parameters quickly. • Dynamic Graphics … uses animated / rotating plots to visualize high dimensional (continuous) data.
    [Show full text]
  • Infovis and Statistical Graphics: Different Goals, Different Looks1
    Infovis and Statistical Graphics: Different Goals, Different Looks1 Andrew Gelman2 and Antony Unwin3 20 Jan 2012 Abstract. The importance of graphical displays in statistical practice has been recognized sporadically in the statistical literature over the past century, with wider awareness following Tukey’s Exploratory Data Analysis (1977) and Tufte’s books in the succeeding decades. But statistical graphics still occupies an awkward in-between position: Within statistics, exploratory and graphical methods represent a minor subfield and are not well- integrated with larger themes of modeling and inference. Outside of statistics, infographics (also called information visualization or Infovis) is huge, but their purveyors and enthusiasts appear largely to be uninterested in statistical principles. We present here a set of goals for graphical displays discussed primarily from the statistical point of view and discuss some inherent contradictions in these goals that may be impeding communication between the fields of statistics and Infovis. One of our constructive suggestions, to Infovis practitioners and statisticians alike, is to try not to cram into a single graph what can be better displayed in two or more. We recognize that we offer only one perspective and intend this article to be a starting point for a wide-ranging discussion among graphics designers, statisticians, and users of statistical methods. The purpose of this article is not to criticize but to explore the different goals that lead researchers in different fields to value different aspects of data visualization. Recent decades have seen huge progress in statistical modeling and computing, with statisticians in friendly competition with researchers in applied fields such as psychometrics, econometrics, and more recently machine learning and “data science.” But the field of statistical graphics has suffered relative neglect.
    [Show full text]
  • Principles of Graph Construction
    PRINCIPLES OF GRAPH CONSTRUCTION Frank E Harrell Jr Department of Biostatistics Vanderbilt University School of Medicine [email protected] biostat.mc.vanderbilt.edu at Jump: StatGraphCourse Office of Biostatistics, FDA CDER [email protected] Blog: fharrell.com Twitter: @f2harrell DIA/FDA STATISTICS FORUM NORTH BETHESDA MD 2017-04-24 Copyright 2000-2017 FE Harrell All Rights Reserved Chapter 1 Principles of Graph Construction The ability to construct clear and informative graphs is related to the ability to understand the data. There are many excellent texts on statistical graphics (many of which are listed at the end of this chapter). Some of the best are Cleveland’s 1994 book The Elements of Graphing Data and the books by Tufte. The sugges- tions for making good statistical graphics outlined here are heavily influenced by Cleveland’s 1994 book. See also the excellent special issue of Journal of Computa- tional and Graphical Statistics vol. 22, March 2013. 2 CHAPTER 1. PRINCIPLES OF GRAPH CONSTRUCTION 3 1.1 Graphical Perception • Goals in communicating information: reader percep- tion of data values and of data patterns. Both accu- racy and speed are important. • Pattern perception is done by detection : recognition of geometry encoding physi- cal values assembly : grouping of detected symbol elements; discerning overall patterns in data estimation : assessment of relative magnitudes of two physical values • For estimation, many graphics involve discrimination, ranking, and estimation of ratios • Humans are not good at estimating differences with- out directly seeing differences (especially for steep curves) • Humans do not naturally order color hues • Only a limited number of hues can be discriminated in one graphic • Weber’s law: The probability of a human detecting a difference in two lines is related to the ratio of the two line lengths CHAPTER 1.
    [Show full text]
  • Statistical Concepts in Metrology — with a Postscript on Statistical Graphics
    NBS Special Publication 747 Statistical Concepts in Metrology — With a Postscript on Statistical Graphics Harry H, Ku NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS iS NBS NBS NBS NBS NBS NBS NBS NBS NBS Nl NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS tS NBS NBS NBS NBS NBS NBS NBS NBS NBS Nl NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS iS NBS NBS NBS NBS NBS NBS NBS NBS NBS NlJ. NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS iS NBS NBS NBS NBS NBS NBS NBS NBS NBS NlJ. NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS tS NBS NBS NBS NBS NBS NBS NBS NBS NBS Nl NBS NBS NBS National Bureau ofStandards NBS NBS tS NBS NBS NBS NBS NBS NBS NBS NBS NBS Nl NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS ^^mS NBS NBS NBS NBS NBS NBS NBS NBS Nl ^^NBS NBS NBS NBS NBS NBS NBS NBS NBS l^mS NBS NBS NBS NBS NBS NBS NBS NBS Nl m he National Bureau of Standards' was established by an act of Congress on March 3, 1901. The m Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research to assure international competi- tiveness and leadership of U.S. industry, science and technology. NBS work involves development and transfer of measurements, standards and related science and technology, in support of continually improving U.S.
    [Show full text]
  • Graph Pie — Pie Charts
    Title stata.com graph pie — Pie charts Description Quick start Menu Syntax Options Remarks and examples References Also see Description graph pie draws pie charts. graph pie has three modes of operation. The first corresponds to the specification of two or more variables: . graph pie div1_revenue div2_revenue div3_revenue Three pie slices are drawn, the first corresponding to the sum of variable div1 revenue, the second to the sum of div2 revenue, and the third to the sum of div3 revenue. The second mode of operation corresponds to the specification of one variable and the over() option: . graph pie revenue, over(division) Pie slices are drawn for each value of variable division; the first slice corresponds to the sum of revenue for the first division, the second to the sum of revenue for the second division, and so on. The third mode of operation corresponds to the specification of over() with no variables: . graph pie, over(popgroup) Pie slices are drawn for each value of variable popgroup; the slices correspond to the number of observations in each group. Quick start Pie chart with slices that reflect the proportion of observations for each level of catvar1 graph pie, over(catvar1) As above, but slices reflect the total of v1 for each level of catvar1 graph pie v1, over(catvar1) As above, but with one pie chart for each level of catvar2 graph pie v1, over(catvar1) by(catvar2) Size of slices reflects the share of each variable in the total of v1, v2, v3, v4, and v5 graph pie v1 v2 v3 v4 v5 As above, and label the first slice with its percentage
    [Show full text]
  • Statistical Graphics Using ODS This Document Is an Individual Chapter from SAS/STAT® 13.2 User’S Guide
    SAS/STAT® 13.2 User’s Guide Statistical Graphics Using ODS This document is an individual chapter from SAS/STAT® 13.2 User’s Guide. The correct bibliographic citation for the complete manual is as follows: SAS Institute Inc. 2014. SAS/STAT® 13.2 User’s Guide. Cary, NC: SAS Institute Inc. Copyright © 2014, SAS Institute Inc., Cary, NC, USA All rights reserved. Produced in the United States of America. For a hard-copy book: No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise, without the prior written permission of the publisher, SAS Institute Inc. For a Web download or e-book: Your use of this publication shall be governed by the terms established by the vendor at the time you acquire this publication. The scanning, uploading, and distribution of this book via the Internet or any other means without the permission of the publisher is illegal and punishable by law. Please purchase only authorized electronic editions and do not participate in or encourage electronic piracy of copyrighted materials. Your support of others’ rights is appreciated. U.S. Government License Rights; Restricted Rights: The Software and its documentation is commercial computer software developed at private expense and is provided with RESTRICTED RIGHTS to the United States Government. Use, duplication or disclosure of the Software by the United States Government is subject to the license terms of this Agreement pursuant to, as applicable, FAR 12.212, DFAR 227.7202-1(a), DFAR 227.7202-3(a) and DFAR 227.7202-4 and, to the extent required under U.S.
    [Show full text]
  • Graphical Perception: Theory, Experimentation, and Application to the Development of Graphical Methods Author(S): William S
    Graphical Perception: Theory, Experimentation, and Application to the Development of Graphical Methods Author(s): William S. Cleveland and Robert McGill Source: Journal of the American Statistical Association, Vol. 79, No. 387 (Sep., 1984), pp. 531-554 Published by: Taylor & Francis, Ltd. on behalf of the American Statistical Association Stable URL: http://www.jstor.org/stable/2288400 Accessed: 01-03-2016 14:55 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Taylor & Francis, Ltd. and American Statistical Association are collaborating with JSTOR to digitize, preserve and extend access to Journal of the American Statistical Association. http://www.jstor.org This content downloaded from 162.105.192.28 on Tue, 01 Mar 2016 14:55:50 UTC All use subject to JSTOR Terms and Conditions Graphical Perception: Theory, Experimentation, and Application to the Development of Graphical Methods WILLIAM S. CLEVELAND and ROBERT McGILL* The subject of graphical methods for data analysis and largely unscientific. This is why Cox (1978) argued, for data presentation needs a scientific foundation. In this "There is a major need for a theory of graphical methods" article we take a few steps in the direction of establishing (p.
    [Show full text]
  • Statistical Graphics Considerations January 7, 2020
    Statistical Graphics Considerations January 7, 2020 https://opr.princeton.edu/workshops/65 Instructor: Dawn Koffman, Statistical Programmer Office of Population Research (OPR) Princeton University 1 Statistical Graphics Considerations Why this topic? “Most of us use a computer to write, but we would never characterize a Nobel prize winning writer as being highly skilled at using a word processing tool. Similarly, advanced skills with graphing languages/packages/tools won’t necessarily lead to effective communication of numerical data. You must understand the principles of effective graphs in addition to the mechanics.” Jennifer Bryan, Associate Professor Statistics & Michael Smith Labs, Univ. of British Columbia. http://stat545‐ubc.github.io/block015_graph‐dos‐donts.html 2 “... quantitative visualization is a core feature of scientific practice from start to finish. All aspects of the research process from the initial exploration of data to the effective presentation of a polished argument can benefit from good graphical habits. ... the dominant trend is toward a world where the visualization of data and results is a routine part of what it means to do science.” But ... for some odd reason “ ... the standards for publishable graphical material vary wildy between and even within articles – far more than the standards for data analysis, prose and argument. Variation is to be expected, but the absence of consistency in elements as simple as axis labeling, gridlines or legends is striking.” 3 Kieran Healy and James Moody, Data Visualization in Sociology, Annu. Rev. Sociol. 2014 40:5.1‐5.5. What is a statistical graph? “A statistical graph is a visual representation of statistical data.
    [Show full text]
  • No Humble Pie: the Origins and Usage of a Statistical Chart
    Journal of Educational and Behavioral Statistics Winter 2005, Vol. 30, No. 4, pp. 353–368 No Humble Pie: The Origins and Usage of a Statistical Chart Ian Spence University of Toronto William Playfair’s pie chart is more than 200 years old and yet its intellectual ori- gins remain obscure. The inspiration likely derived from the logic diagrams of Llull, Bruno, Leibniz, and Euler, which were familiar to William because of the instruction of his mathematician brother John. The pie chart is broadly popular but—despite its common appeal—most experts have not been seduced, and the academy has advised avoidance; nonetheless, the masses have chosen to ignore this advice. This commentary discusses the origins of the pie chart and the appro- priate uses of the form. Keywords: Bruno, circle chart, Euler, Leibniz, Llull, logic diagrams, pie chart, Playfair 1. Introduction The pie chart is more than two centuries old. The diagram first appeared (Playfair, 1801) as an element of two larger graphical displays (see Figure 1 for one instance) in The Statistical Breviary, whose charts portrayed the areas, populations, and rev- enues of European states. William Playfair had previously devised the bar chart and was first to advocate and popularize the use of the line graph to display time series in statistics (Playfair, 1786). The pie chart was his last major graphical invention. Playfair was an accomplished and talented adapter of the ideas of others, and although we may be confident that we know his sources of inspiration in the case of the bar chart and line graph, the intellectual motivations for the pie chart and its parent, the circle chart, remain obscure.
    [Show full text]
  • DEVELOPMENTS in STATISTICAL GRAPHICS 1960-1980 Alan Julian Izenman the U~Ivcrsity of Minncsot
    DEVELOPMENTS IN STATISTICAL GRAPHICS 1960-1980 by Alan Julian Izenman The U~ivcrsity of Minncsot~ Teclmical Report No. 335 December 1978 " SUMMARY i This paper presents an historical perspective on the development of graphical methods in data analysis during the twenty years from 1960 to 1980. Three main periods of development are identified: pre-1960; the 1960's; and the 1970's. Discussion of various types of univariate and multivariate data graphics is given including methods for probability plotting. Possible future directions for statistical graphics are also mentioned. Key words: probability plots, Q-Q plots, semigraphical displays, scatter­ plots, residual analysis, outliers, multivariate data analysis, computer graphics. !' ~ _;;;; • \ 1. INTRODUCTION In recent years there has been a noticeable rise of concern among members of the statistical profession about the nature of and standards for statistical graphics, with special sessions (1976 Boston ASA Meeting, 1978 San Diego ASA Meeting) and conferences (1977 Sheffield Conference, 1978 1st Social Graphics Conference in Leesburg, Virginia) on the subject now taking place on a regular basis. A result of all this concern has been an improvement in the formulation (Tufte (1978), Cox (1978), Fienberg (1978)) and evaluation (Wainer and Reiser (1976), Wainer (1977)) of rules for drawing graphs. A great deal of the credit for this 'movement to better graphics' is due to the widespread availability of- electronic high-speed computers and their associated graphics systems. With computer hardware becoming cheaper every year, the type of exclusivity in this field that once belonged to research establishments such as Bell Laboratories appears to be fast disappearing.
    [Show full text]
  • Principles of Statistical Graphics
    Principles of Statistical Graphics Principles of Statistical Graphics 1 What’s wrong with this? Principles of Statistical Graphics 2 What’s wrong with this? How would you graph the same data? Principles of Statistical Graphics 2 Cleveland’s paradigm A graph encodes quantitative and categorical information using symbols, geometry and color. Graphical perception is the visual decoding of the encoded information. The graph may be beautiful but a failure: the visual decoding has to work. To make graphs work we need to understand graphical perception: what the eye sees and can decode well. visual perception. Principles of Statistical Graphics 3 Cleveland’s paradigm A graph encodes quantitative and categorical information using symbols, geometry and color. Graphical perception is the visual decoding of the encoded information. The graph may be beautiful but a failure: the visual decoding has to work. To make graphs work we need to understand graphical perception: what the eye sees and can decode well. visual perception. Principles of Statistical Graphics 3 Cleveland’s paradigm A graph encodes quantitative and categorical information using symbols, geometry and color. Graphical perception is the visual decoding of the encoded information. The graph may be beautiful but a failure: the visual decoding has to work. To make graphs work we need to understand graphical perception: what the eye sees and can decode well. visual perception. Principles of Statistical Graphics 3 Cleveland’s paradigm A specification and ordering of elementary graphical-perception tasks. Ten properties of graphs: Angle Position along a Area common scale Colour hue Position along Colour saturation identical, Density (amount of non-aligned scales black) Slope Length (distance) Volume Principles of Statistical Graphics 4 Cleveland’s paradigm A specification and ordering of elementary graphical-perception tasks.
    [Show full text]